Interpretive Summary: Stinging wasps are of concern to orchardists because of their potential to damage ripe fruit and as a hazard to field workers. Researchers at the USDA-ARS Yakima Agricultural Research Laboratory, in collaboration with university researchers, are developing information on life history, distribution, and responses to baits and chemical attractants for yellowjackets, hornets, and paper wasps. It was determined that a yellowjacket species that is common in the U.S., Vespula squamosa, also occurs in the highlands of Guatemala, Central America. This wasp has a nesting biology in Guatemala similar to that in the U.S. Such information on foreign pests helps us to assess potential risks of pest movement with commodities and the potential of such pests to be invasive.

Technical Abstract:
Southern yellowjackets, Vespula squamosa (Drury) were collected at sites in Guatemala, in the Departments of Baja Verapaz, El Progresso, and Zacapa. Collection localities ranged in elevation from 500 to 1880 m. These locations were forested, or partially forested with some pasture land and coffee plantings, Coffea arabica L. Two active colonies of this wasp were located, killed, excavated, and analyzed in May of 2006. The two colonies were subterranean, and the nests had 9 and 11 layers of paper comb completely surrounded with external paper envelope. The two nests included 10,581 and 20,715 cells, with 2,818 and 6,105 workers, 203 and 313 queens, and 790 and 454 males respectively. Samples of queens from each nest were dissected. These included numerous queens that were mated and possessed mature eggs, as well as numbers of queens that were unmated and had no eggs. Workers from each nest showed no ovarian development. The nest sizes and populations of wasps for these colonies were within ranges of those reported for nests of this species in North America.